"We have a relationship with them, but unfortunately our mission is to release quality titles. Their titles are good, but not good as we expected. That's our reason. They always ask us to localize their titles, but at this moment we answer with 'we're sorry'."
Atlus, Mastiff, O3 (who did the amazing localization of Idea Factory's Chaos Wars) and other small publishers are still a possibility, but NIS definitely doesn't have interest in working with the company. Which is good, because that particular bridge is pretty well toasted.